BTKUSA DUAL DIFFERENTIAL MOUNT G SERIES M240i/M340i/M440i/A9X SUPRA
ALL COMPONENTS FROM THE BUSHING, BOLTS, TO THE FULL BILLET ASSEMBLY ARE PROUDLY MADE IN THE USA.
MADE IN SAN CLEMENTE, CA 🇺🇸
ALL HARDWARE FOR ASSEMBLY INCLUDED
The BuiltToKillUSA Differential Dual Mount is designed to reinforce one of the G-series platform’s known weak points. Designed for the G-series M240i, M340i, M440i, and A90/A91 Supra, unlike most dual diff mounts on the market this system utilizes a bushing rather than completely solid mounting to the chassis. We did this to prevent unwanted noise, vibration, and hardness. With the BUILTTOKILLUSA dual diff mount you get all the benefit without sacrificing comfort of your daily driver. Our dual diff mount keeps the differential stable under hard acceleration, aggressive launches, and spirited driving. This reduces flex and sharpens overall driveline response.
This system requires drilling a single mounting point into the subframe. To make installation straightforward, a properly sized drill bit is included in the kit. All supplied hardware is stainless steel, ensuring durability and resistance to corrosion over time.
• Introduces an additional reinforced mounting point to better control differential movement under load
• Enhances traction, throttle response, and overall drivetrain stability
• Utilizes a threaded steel backing plate for a secure, reliable mount—no rivet nuts or compromise hardware
• Complete hardware kit included, along with the required drill bit for installation
• Installation requires drilling one precise hole in the subframe
• Designed as a straightforward bolt-on solution with no need to remove factory mounting components
WHAT IS A DUAL DIFF MOUNT AND HOW CAN IT BENEFIT MY BUILD?
1. Improved load distribution
• The mount ties both sides of the differential into the subframe instead of relying on a single ear or bushing.
• This spreads torque load more evenly under hard acceleration, launches, and aggressive shifts.
• That’s especially important on higher-torque cars where the diff wants to rotate upward.
2. Reduced differential movement
• Less movement = more consistent driveline geometry.
• This directly helps with:
◦ Reduced wheel hop
◦ More predictable traction
◦ Less shock loading on axles and bushings
3. Structural rigidity
• All US 6061 machined aluminum
Why We Use a Bushing Instead of a Solid Mount
Most dual diff mounts on the market go fully solid but that isn’t always the best solution.
Our system uses a high-durometer 80A bushing to control differential movement without completely eliminating it. Under hard acceleration and clutch dumps, the bushing compresses slightly to absorb shock, then immediately stabilizes the drivetrain. This reduces unwanted flex while preventing harsh load spikes from being transferred directly into the subframe and mounting points.
The result:
- More controlled power delivery
- Reduced drivetrain shock and stress
- Improved traction under load
- Significantly less NVH compared to solid mounts
A full solid mount may eliminate all movement, but it also transfers every bit of force into the chassis. Our approach strikes the balance of delivering near-solid performance while protecting the car and keeping it streetable.